export const adapt = (designWidth, rem2px) => {
  var d = window.document.createElement('div')
  d.style.width = '1rem'
  d.style.display = 'none'
  var head = window.document.getElementsByTagName('head')[0]
  head.appendChild(d)
  var defaultFontSize = parseFloat(window.getComputedStyle(d, null).getPropertyValue('width'))
  var st = document.createElement('style')
  var portrait = '@media screen and (min-width: ' + window.innerWidth + 'px) {html{font-size:' + ((window.innerWidth / (designWidth / rem2px) / defaultFontSize) * 100) + '%;}}'
  var landscape = '@media screen and (min-width: ' + window.innerHeight + 'px) {html{font-size:' + ((window.innerHeight / (designWidth / rem2px) / defaultFontSize) * 100) + '%;}}'
  st.innerHTML = portrait + landscape
  head.appendChild(st)
  return defaultFontSize
}
